1. Field of the Disclosure
The present disclosure relates to a circuit breaker capable of providing information on a trip cause, and more particularly, to a circuit breaker having a trip cause indicating mechanism for providing information on whether a trip cause results from a fault current or an under voltage.
2. Background of the Disclosure
Generally, a circuit breaker is an apparatus for protecting a circuit by opening or closing the circuit between a power side and a load side, or by breaking the circuit in the occurrence of an electrical fault such as a ground fault or an electrical shortage. That is, the circuit breaker converts a status of an electrical circuit to an ‘OFF’ or ‘ON’ status by a user's manipulation, and breaks the circuit automatically by trip operation in the occurrence of an overload or an electrical shortage, thereby protecting load side components and the circuit. In the conventional circuit breaker, when the trip operation is performed due to a fault current, a trip indicating contact switch for providing trip information to a manager of an electrical facility or a user is operated.
The conventional trip status indicating mechanism for a circuit breaker will be explained with reference to FIGS. 1 and 2.
FIG. 1 is a view showing that a trip indicating contact switch of a circuit breaker is not operated in accordance with the conventional art, and FIG. 2 is a view showing that a trip indicating contact switch of a circuit breaker is operated in accordance with the conventional art.
The conventional trip indicating contact switch of a circuit breaker comprises a trip indicating switch 1, a driving force transmission lever 2, a magnetic trip mechanism 3. Reference numeral 4 in FIGS. 1 and 2 denotes a switch driving lever 4 configured to operate the trip indicating switch 1 to an ‘ON’ or ‘OFF’ position.
The operation of the conventional trip indicating contact switch of a circuit breaker will be explained as follows.
In an electric power user such as a factory, a transformer is installed as an electricity receiving apparatus, and a large capacity circuit breaker such as an air circuit breaker is installed to connect with an output of the transformer. This large capacity circuit breaker comprises a controller called as ‘Over Load Relay’ or ‘Over Current Relay’ (which is abbreviated as OCR hereinafter). The OCR detects a fault of a current which flows on a circuit by being electrically connected to the circuit, such as an electrical shortage, an over current or a ground fault. Then, the OCR outputs a trip command signal to a trip mechanism when a fault has been detected. In response to the trip command signal, the trip mechanism triggers a switching mechanism for a trip operation.
Upon receiving a corresponding trip command signal transmitted from the OCR, the magnetic trip mechanism 3 triggers the switching mechanism so as to break a circuit. As a movable contact (not shown) is separated from a fixed contact, a trip operation is completed. Here, the driving force transmission lever 2 forwardly rotates by interlocking with components which move to a front side of the magnetic trip mechanism 3, thereby pushing a switch operation lever 6 of the trip indicating switch 1. As a result, the trip indicating switch 1 as a micro switch outputs a trip indicating signal. When the circuit breaker is reset after being tripped, the trip indicating switch 1 rotates to an initial position by a return spring (not shown). At the same time, the trip indicating switch 1 is also initialized to stop outputting a trip indicating signal.
The conventional circuit breaker may have a trip operation due to a low voltage on the circuit (hereinafter, will be referred to as ‘Under Voltage Trip’), as well as a fault current such as an electrical shortage. However, the conventional circuit breaker is configured to output a trip indicating signal only when a trip operation occurs due to a fault current. Accordingly, it is difficult to check whether a trip operation has occurred due to a fault current or an under voltage.
In the event of an under voltage trip, a remote monitoring center or a central monitoring and supervising equipment could not recognize the under voltage trip. Accordingly, it was difficult to recognize a cause of a trip occurrence, and to determine a re-closing command for the circuit breaker after the trip occurrence.